Hydrotunnel boat



' Jan. 28, 1969 v. B. KORIAGIN HYDRQTUNNEL BOAT Sheet Filed Dec. 20, 1966 I N VE N TOR. fl AAA/A F44 WM/1064A A/fame ya far A /ram rsfmzop 5 zaaw/n/ Jan. 28, 1969 v. B. KORIAGIN 2 HYDROTUNNEL BOAT Filed Dec. 20, 1966 United States Patent 3,424,120 HYDROTUNNEL BOAT Vsevolod B. Koriagiu, 1534 Raymond Ave, Glendale, Calif. 91201 Filed Dec. 20, 1966, Ser. No. 602,876 US. Cl. 114-67 13 Claims Int. Cl. B63b 1/22, 1/36 ABSTRACT OF THE DISCLOSURE A hydroplane boat with air-borne capabilities at cruising speeds having anti-pitch-up bow control means including an aerodynamic hinged flap operable to vary the effective coefficient of lift of an aerodynamically operative surface at the bow entrance end of an axially extending bottom tunnel, hinged movement of the flap being effected by a water controlled flap or vane which holds the hinged flap in closed position when the boat is on the water, but moves it to apply corrective forces without changing the angle of attack, when the boat leaves the water.

A further feature includes an improved hull superstructure which provides tunnels on opposite sides of the hull, these tunnels having intakes at the after part of the upper deck and exits below the hull at the rear end of the boat, automatically controlled flaps being provided for controlling air stream flow through the tunnels and varying pressures therein and the lifting forces at the stern of the boat.

The present invention relates generally to a water-borne vehicle, and more particularly to a hydroplane boat with air-borne capabilities at crusing speeds.

The hydroplane type boat is designed to travel on water with its weight entirely supported by the hydrodynamic forces acting on its hull bottom. However, actual experience with this type of boat points to the fact that a substantial portion of the weight is supported by the aerodynamic forces when traveling at high speeds. The hydroplane is noted for its tendency to pitch-up and flip completely over onto its back when traveling at high speeds over choppy waters and/0r under gusty air conditions. This dangerous tendency results from conditions which include the aerodynamic forces acting on its hull body in the hereinafter noted manner. The hydroplane, traveling in its normal planing attitude, obtains its principal aerodynamic lift on the hull body under surface between the sponsons as a result of the air pressure created by the hydorplanes forward speed.

With an increase in speed, the boat becomes more and more air-borne than water-borne until it approaches substantially a condition of being entirely air-borne. When this point is reached, the bow then tends to rise because the center of the aerodynamic pressure lift is acting at the bow ahead of the center of gravity of the boat, which is located near the stern of hydrodynamic design reasons. The resulting pivoting motion about the stern is known as pitch-up. The pitch-up motion increases magnitude of the aerodynamic force due to an increase in the angle of attack of the body with respect to the air flow in the same manner as it does on an air-foil. The above motion constitutes an unstable condition and, more often than not, produces a flip.

The above aerodynamic lift results in lower boat drag than the hydrodynamic lift, and thus permits the boat to attain an increase in speed for the same horsepower. The apparent gain in speed by the hydroplane by being airborne, in so far as can be safely accomplished, becomes more apparent in the catamaran type of boat design. The catamaran has sponsons which extend the full length of the hull body instead of substantially half the length, as in the case of the hydroplane. Therefore, the catamaran is also noted for its tendency to pitch-up and flip for the same reasons as in the case of the hydroplane.

With the inherent difliculties and problems associated with the hydroplane and catamaran watercraft as stated above, the present invention has for one object the provision of means for the prevention and control of the pitch-up characteristics inherent particularly in this type of craft. For such purpose, an auxiliary aerodynamic body in the form of a tunnel shaped structure is integrated into the basic hydroplane hull design. This structure provides aerodynamic lift aft of the center of gravity of the boat and assures against any pitch-up motion under normal air-borne operating conditions.

It is a further object to provide anti-pitch-up control means at the bow of the hydroplane or catamaran boat to automatically counteract and control forced pitch-up motions which may be due to more severe wave impacts. For such purpose, a tunnel structure is provided in the hull design at the bow of the boat. While the location of this tunnel may vary, it is disclosed as being positioned between the two sponsons of the hull structure.

Still another object of the herein described invention is to provide means for making boats of the hydroplane and catamaran type more comfortable when riding over waves, and for improving the speed capabilities of these crafts as well as the fuel economy. These improvements result from the fact that an air-borne vehicle is subjected to fewer and less severe wave impacts, and olfer less drag resistance to forward motion for the same weight than boats which are completely water-borne.

Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.

Referring to the accompanying drawings, which are for illustrative purposes only:

FIG. 1 is a perspective view of a boat embodying the features of the present invention;

FIG. 2 is a fragmentary perspective view of the hull structure of the boat, as viewed from the underside;

FIG. 3 is a side elevational view of the same;

FIG. 4 is a vertical sectional view through one of the superstructure tunnels diagrammatical showing the longitudinal contour thereof, taken substantially on line 4-4 of FIG. 1;

FIG. 5 is a horizontal sectional view showing the contour of the tunnel structure, taken substantially on line 5-5 of FIG. 1;

FIGS. 6 and 7 are views diagrammatically illustrating the operation of the side flap segments of the superstructure tunnel;

FIG. 8 is an enlarged fragmentary view showing the mounting of the tail planing member at the hull stern;

FIG. 9 is a bottom plan view of the same; and

FIG. 10 is a view diagrammatically showing the control mechanisms.

Referring more specifically to the drawings, for illustrative purposes, the craft of the present invention is shown in FIG. 1 as being comprised generally of two major assemblies, namely, a hull assembly A and a superstructure assembly B. While these assemblies may vary as to details of construction, the hull assembly A is watertight and buoyant, and may be interiorly arranged to accommodate passengers, power plant, fuel, cargo and the like. The superstructure assembly B is arranged to provide stabilizing air lift tunnel structures in the after end of the craft as will hereinafter be more fully explained.

The hull assembly A is in general of the type utilized for hydroplanes, but has been modified to include the features of construction of the present invention. As disclosed in FIGS. 1 and 2, the hull assembly A is fabricated to provide a broad beamed bow portion having a more or less flat exposed upper deck 11. From the bow portion, there rearwardly extends an after hull structure 12 of relatively narrow beam, as compared to the beam of the bow portion.

The opposite sides of the bow portion are constructed to provide sponsons 13 and 14, respectively. These sponsons are of conventional construction and project downwardly below an intermediate bottom surface 15 which is carried forwardly in an upwardly curved portion 15a at the bow end, and extended into a substantially planar surface 15b in the after hull 12- Boats of the above described character operate in the ground effect mode, and air pressurized in the bow tunnel by the vehicle motion is kept from being deflected downwardly due to proximity of the underlying water surface. The air pressure is reduced by the vehicle moving upwardly from the water due to a wave impact and/ or air gust. Generally, this motion is accompanied by pitchup and a concomitant increase in the angle of attack of the hull body as an aerodynamic lifting surface. This increase in the angle of attack creates additional air load on the hull. The added increment of air load is concentrated at the forward portion of the hull, and when the additional air lift more than counterbalances the reduction in the air load on the underside of the hull, a pitchup moment results to cause the vehicle to overturn completely.

In order to correct the foregoing situation, an aerodynamic flap 17 is located at the tunnel entrance at the bow of the hull. This flap is supported along an edge hinge 18 at its forward edge for swinging movements between a closed position as shown in FIG. 1 and adjusted open positions as shown in FIG. 3. While this flap is shown as being located between the sponsons, it is within the contemplation of the present invention that multiple flaps might be used which are placed on opposite sides of a single hull type boat.

For normal operating conditions, the flap is in closed or down position, as shown in FIG. 1, to provide an upward air lift on the bow. The flap is deflected to an up position to create a downward air load for counteracting a pitch-up maneuver. Provision may be made for either manual or automatic adjustment of this flap. For manual adjustment, this may be accomplished simply by a manually adjustable lever and connecting link to the flap.

For automatically controlling the flap position, there is provided a water actuated flap 19 which may be positioned at the after end of one of the sponsons, or if desired two such flaps may be utilized, one at the end of each of the sponsons. The flap 19 is in each case supported at its forward edge on a hinge 20 for swinging movements, the flap 19 being connected through servo means such as a link 21, FIG. 10, in such a manner that movement of the flap 19 in a counter clockwise direction will move the flap 17 towards its closed position, and vice versa. Thus, the hydrodynamic flap 19, when submerged, tends to keep the aerodynamic flap 17 in closed position during forward movement of the boat. However, emergence of the flap 19 from the water by a pitch-up maneuver, acts to raise the flap 17 as a result of the air load thereon. When this occurs, the air pressure under the bow will be materially reduced and force the hull to be pitched downwardly due to a reduction in up lift of the bow. Upon contact of the flap 19 with the water, flap 17 will be returned to its normal position.

The action of the flap 19 in controlling the operation of flap 17 may be supplemented and overridden by manually operable means under the control of the boat operator. As illustrative of such manual control, there is shown in FIG. 10 a foot lever 22 which is centrally ful crumed and connected at its delivery end with the flap 17 by means of a connecting link member 23. While a foot actuated lever has been shown, the lever may be hand operated if desired. With this added overriding control, the

operator can alleviate a severe wave impact by premeditated action of the manual control.

The superstructure assembly B, as shown in FIG. 1 is provided as an integrated structure associated with the after hull portion 12 and in general lies aft of the bow portion 10 of the hull assembly. The superstructure as sembly is constructed of suitable material and is fabricated to provide additional tunnel means at the stern portion of the hull.

More specifically, the superstructure assembly B is of shell-like construction with an upper wall or deck 24 which is laterally connected with depending side walls 25 and 26. The wall 24 is centrally supported longitudinally thereof by means of a central partition 27 which extends along the upper surface of the after hull 12 to form a longitudinally extending central wall structure which cooperates with the side walls 25 and 26 to provide longit-udinally extending tunnels 28 and 29 which are positioned on opposite sides of the after hull 12. These tunnels have entrance openings 30 and 31 respectively which are positioned above and at the after part of the upper deck 11 of the hull assembly A. It will be observed that at these tunnel openings, portions of the deck 11 as indicated at 11a and 11b are curved downwardly towards the forward ends of the tunnel to improve the inflow characteristics of the air. Each tunnel, as diagrammatically shown in FIGS. 4 and 5, is of decreasing area from its entrance to its exit at the rear end of the boat. Control flaps 32 and 33 are supported upon a common shaft 34 for pivotal hinged movement along their forward edges into positions for controlling air stream flow through the associated tunnels, whereby the pressures therein may be varied to control the lifting forces at the stern portion of the boat. The flaps 32 and 33 are actuable as a unit through a lever arm 35 which is connected to a link member 36 that is operable by means of a pivoted hand lever 37, or other suitable means in the cockpit 38 of the boat to control the position of the flaps and the resulting air lift created in the tunnels.

As shown in FIGS. 1 and 3, the side walls 25 and 26 are respectively provided with a forward hinged extension 39 and aft hinged extension 40, these extensions being hinged to the associated side wall along their upper edge margins. These extensions are provided to minimize depressurization of the associated tunnel air through the gap between the lower end of the side wall and the water surface which would permit the escape of air and reduce the lifting capacity of the tunnel arrangement. On the other hand, any portion of the side walls submerged in the water adds substantially to the water drag and also tends to reduce turning capability of the boat. For this reason, the extensions 39 and 40 are hinged.

As shown in FIG. 6, the extension 39 is swingable in an inboard direction only, being opposed from hinging outboard movement by a stop plate 41. This prevents the extension from swinging in an outboard direction which would cause venting of the pressurized air and a reduction in the aerodynamic lift in the tunnel.

The aft extension 40, as shown in FIG. 7 is provided with a spring 42 of sufficient stiffness to keep the extension from deflecting in an outboard direction due to operating internal pressure loads in the tunnel only, but to permit outward hinging under the increased water pressure loads when the extension is in submerged position. The extension is free to deflect in an inboard direction in the same manner as the extension 39. The extension 41] offers the least resistance to the vehicle turning capability. Both extensions have their lowermost edges inwardly turned as respectively indicated at 39a and 40a to fold inwardly when submerged during water-borne speed conditions.

As shown in FIGS. 8 and 9, the after hull 12 has its side walls tapered to provide a pointed stern on the boat. Also, it will be seen that the bottom surface at the stern is upwardly offset and rearwardly upwardly inclined to provide a planar surface 150 at the stern. A tail planing member 43 is provided below the surface 150, this member being hinged at 44 at its innermost end for swinging adjustment. This planing member provides in effect a boat of greater length, and in this respect becomes less responsive to the severe impact loads and pitching motions due to occasional high waves during operating conditions. A more comfortable riding boat is thus provided during operation in rough water conditions. Provision is made for adjusting the trim of the tail planing member by the boat operator. Any suitable mechanism may be provided for this purpose. For illustrative purposes, the member 43 is swingable by means of a connector member 43a at its trailing end, this connector member having a connection with a slidably mounted sleeve 43b. This sleeve has its upper end in threaded connection with a raising and lowering screw 44a which carries a cable wheel 45 at its upper end over which a cable 46 is trained. This cable is shown as extending to the boat cockpit, FIG. 10, where it is connected with a manually operable crank drum 47. This arrangement permits the operator to trim the boat for any variations in the center of gravity of the boat and water conditions to obtain the best speed and riding comfort.

For propelling the boat, water screws 48 and 49 are operatively positioned at the aft ends of the sponsons. 13 and 14, as shown in FIGS. 2 and 3. The screws 48 and 49 are respectively carried by drive shafts 50 and 51 of associated engines 52 and 53 mounted in the sponsons. This location of the screws provides an additional measure of safety in a pitch-up condition, over and above that which is provided by the action of flap 17, In the event that the boat should rise sufficiently above the water for the screws to be withdrawn from the water, the thrust of the screws would be reduced to zero and, there would be an automatic slowing down of the boat to a slower safer speed. Location of the engines in the sponsons has the additional avantage of concentrating the weight of the power plant in the bow portion of the boat where it will directly and most effectively oppose the impact loads which would otherwise be transmitted to the hull structure and react to the discomfort of the passengers.

At the stern of the boat conventional water fins 54 and air fin 55 are provided for stabilizing the stern portion of the boat. Likewise a water rudder 56 and air rudder 57 provide steering means, these rudders being connected with conventional control mechanism (not shown) operable by the pilot.

From the foregoing description and drawings, it will be clearly evident that the delineated objects of the invention will be accomplished.

Various modifications may suggest themselves to those skilled in the art without departing from the spirit of my invention, and, hence, I do not wish to be restricted to the specific form shown or uses mentioned except to the extent indicated in the appended claims.

I claim:

1. In a water-borne vehicle:

(a) a buoyant hull having an axially extending bottom tunnel at its bow end;

(b) surface means adjacent the entrance end of said tunnel to aerodynamically produce a lifting force during forward movement of the vehicle; and

(c) flap means adjustable to vary the effective area of said surface means to change its coeflicient of lift.

2. In a water-borne vehicle according to claim 1, wherein said hull includes spaced sponsons and said tunnel is positioned there'between, said flap means being positioned at the tunnel entrance.

3. In a Water-borne vehicle according to claim 1,

including actuating means for varying the position of said flap means.

4. In a water-borne vehicle:

(a) a buoyant hull having an axially extending bottom tunnel at its bow end;

(b) surface means adjacent the entrance end of said tunnel to aerodynamically produce a lifting force during forward movement of the vehicle;

(c) flap means adjustable to vary the coefficient of lift of said surface means; and

(d) actuating means for varying the position of said flap means, including a water moved member.

5. In a water-borne vehicle:

(a) a buoyant hull;

(b) a superstructure on said hull providing air flow tunnel means having a forward air entrance adjacent a top side of said hull and an air exit adjacent a bottom side of said hull; and

(0) variable flap means for varying and controlling the flow of air through said tunnel means.

6. In a water-borne vehicle according to claim 5, wherein the area of said tunnel means reduces as it approaches said exit.

7. In a water-borne vehicle according to claim 5, wherein the flap means includes a horizontally hinged flap at the exit end of the tunnel means.

8. In a water-borne vehicle according to claim 5, wherein the flap means includes spaced apart side flaps supported for swinging movements transversely with respect to the flow axis of the tunnel means.

9. In a water-borne vehicle according to claim 5, wherein the air flow tunnel means comprises separated air flow tunnels positioned on opposite sides of the hull center line.

10. In a water-borne vehicle according to claim 9, including an adjustable stem planing member suspended from the hull bottom between said air flow tunnels.

11. A water-borne vehicle, comprising:

(a) a buoyant hull having spaced sponsons on opposite sides of a bow tunnel having an aerodynamic surface therein, and rearwardly extending central portion;

(b) a superstructure on said hull having parts providing air flow tunnels respectively on opposite sides of said central portion, said tunnels having air entrance openings respectively adjacent the after ends of said sponsons.

12. A water-borne vehicle according to claim 11, including power means in each of said sponsons having a driving connection with a screw propeller positioned ad jacent the entrance end of the air entrance tunnel associated therewith.

13. A water-borne vehicle according to claim 11, including means for respectively controlling and varying the aerodynamic lift characteristics of said tunnels.

References Cited UNITED STATES PATENTS 1,412,848 4/1922 Dunajeff 11466.5 1,509,284 9/1924 Clay 11466.5 2,272,661 2/ 1942 Finley 11466.5 3,094,962 6/1963 Goar 114-665 FOREIGN PATENTS 702,733 1/1931 France.

ANDREW H. FARRELL, Primary Examiner.

US. Cl. X.R. 

